2 * FreeRTOS Kernel V10.0.0
\r
3 * Copyright (C) 2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
\r
5 * Permission is hereby granted, free of charge, to any person obtaining a copy of
\r
6 * this software and associated documentation files (the "Software"), to deal in
\r
7 * the Software without restriction, including without limitation the rights to
\r
8 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
\r
9 * the Software, and to permit persons to whom the Software is furnished to do so,
\r
10 * subject to the following conditions:
\r
12 * The above copyright notice and this permission notice shall be included in all
\r
13 * copies or substantial portions of the Software. If you wish to use our Amazon
\r
14 * FreeRTOS name, please do so in a fair use way that does not cause confusion.
\r
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
\r
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
\r
18 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
\r
19 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
\r
20 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
\r
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
\r
23 * http://www.FreeRTOS.org
\r
24 * http://aws.amazon.com/freertos
\r
26 * 1 tab == 4 spaces!
\r
30 * This demo application creates six co-routines and two tasks (three including
\r
31 * the idle task). The co-routines execute as part of the idle task hook.
\r
33 * Five of the created co-routines are the standard 'co-routine flash'
\r
34 * co-routines contained within the Demo/Common/Minimal/crflash.c file and
\r
35 * documented on the FreeRTOS.org WEB site.
\r
37 * The 'LCD Task' rotates a string on the LCD, delaying between each character
\r
38 * as necessitated by the slow interface, and delaying between each string just
\r
39 * long enough to enable the text to be read.
\r
41 * The sixth co-routine and final task control the transmission and reception
\r
42 * of a string to UART 0. The co-routine periodically sends the first
\r
43 * character of the string to the UART, with the UART's TxEnd interrupt being
\r
44 * used to transmit the remaining characters. The UART's RxEnd interrupt
\r
45 * receives the characters and places them on a queue to be processed by the
\r
46 * 'COMs Rx' task. An error is latched should an unexpected character be
\r
47 * received, or any character be received out of sequence.
\r
49 * A loopback connector is required to ensure that each character transmitted
\r
50 * on the UART is also received on the same UART. For test purposes the UART
\r
51 * FIFO's are not utalised in order to maximise the interrupt overhead. Also
\r
52 * a pseudo random interval is used between the start of each transmission in
\r
53 * order that the resultant interrupts are more randomly distributed and
\r
54 * therefore more likely to highlight any problems.
\r
56 * The flash co-routines control LED's zero to four. LED five is toggled each
\r
57 * time the string is transmitted on the UART. LED six is toggled each time
\r
58 * the string is CORRECTLY received on the UART. LED seven is latched on should
\r
59 * an error be detected in any task or co-routine.
\r
61 * In addition the idle task makes repetative calls to
\r
62 * prvSetAndCheckRegisters(). This simply loads the general purpose registers
\r
63 * with a known value, then checks each register to ensure the held value is
\r
64 * still correct. As a low priority task this checking routine is likely to
\r
65 * get repeatedly swapped in and out. A register being found to contain an
\r
66 * incorrect value is therefore indicative of an error in the task switching
\r
71 /* Scheduler include files. */
\r
72 #include "FreeRTOS.h"
\r
75 #include "croutine.h"
\r
77 /* Demo application include files. */
\r
78 #include "partest.h"
\r
79 #include "crflash.h"
\r
81 /* Library include files. */
\r
82 #include "DriverLib.h"
\r
84 /* The time to delay between writing each character to the LCD. */
\r
85 #define mainCHAR_WRITE_DELAY ( 2 / portTICK_PERIOD_MS )
\r
87 /* The time to delay between writing each string to the LCD. */
\r
88 #define mainSTRING_WRITE_DELAY ( 400 / portTICK_PERIOD_MS )
\r
90 /* The number of flash co-routines to create. */
\r
91 #define mainNUM_FLASH_CO_ROUTINES ( 5 )
\r
93 /* The length of the queue used to pass received characters to the Comms Rx
\r
95 #define mainRX_QUEUE_LEN ( 5 )
\r
97 /* The priority of the co-routine used to initiate the transmission of the
\r
98 string on UART 0. */
\r
99 #define mainTX_CO_ROUTINE_PRIORITY ( 1 )
\r
101 /* Only one co-routine is created so its index is not important. */
\r
102 #define mainTX_CO_ROUTINE_INDEX ( 0 )
\r
104 /* The time between transmissions of the string on UART 0. This is pseudo
\r
105 random in order to generate a bit or randomness to when the interrupts occur.*/
\r
106 #define mainMIN_TX_DELAY ( 40 / portTICK_PERIOD_MS )
\r
107 #define mainMAX_TX_DELAY ( ( TickType_t ) 0x7f )
\r
108 #define mainOFFSET_TIME ( ( TickType_t ) 3 )
\r
110 /* The time the Comms Rx task should wait to receive a character. This should
\r
111 be slightly longer than the time between transmissions. If we do not receive
\r
112 a character after this time then there must be an error in the transmission or
\r
113 the timing of the transmission. */
\r
114 #define mainCOMMS_RX_DELAY ( mainMAX_TX_DELAY + 20 )
\r
116 /* The task priorites. */
\r
117 #define mainLCD_TASK_PRIORITY ( tskIDLE_PRIORITY )
\r
118 #define mainCOMMS_RX_TASK_PRIORITY ( tskIDLE_PRIORITY + 1 )
\r
120 /* The LED's toggled by the various tasks. */
\r
121 #define mainCOMMS_FAIL_LED ( 7 )
\r
122 #define mainCOMMS_RX_LED ( 6 )
\r
123 #define mainCOMMS_TX_LED ( 5 )
\r
125 /* The baud rate used by the UART comms tasks/co-routine. */
\r
126 #define mainBAUD_RATE ( 57600 )
\r
128 /* FIFO setting for the UART. The FIFO is not used to create a better test. */
\r
129 #define mainFIFO_SET ( 0x10 )
\r
131 /* The string that is transmitted on the UART contains sequentially the
\r
132 characters from mainFIRST_TX_CHAR to mainLAST_TX_CHAR. */
\r
133 #define mainFIRST_TX_CHAR '0'
\r
134 #define mainLAST_TX_CHAR 'z'
\r
136 /* Just used to walk through the program memory in order that some random data
\r
137 can be generated. */
\r
138 #define mainTOTAL_PROGRAM_MEMORY ( ( unsigned long * ) ( 8 * 1024 ) )
\r
139 #define mainFIRST_PROGRAM_BYTES ( ( unsigned long * ) 4 )
\r
141 /* The error routine that is called if the driver library encounters an error. */
\r
144 __error__(char *pcFilename, unsigned long ulLine)
\r
149 /*-----------------------------------------------------------*/
\r
152 * The task that rotates text on the LCD.
\r
154 static void vLCDTask( void * pvParameters );
\r
157 * The task that receives the characters from UART 0.
\r
159 static void vCommsRxTask( void * pvParameters );
\r
162 * The co-routine that periodically initiates the transmission of the string on
\r
165 static void vSerialTxCoRoutine( CoRoutineHandle_t xHandle, unsigned portBASE_TYPE uxIndex );
\r
168 * Writes a string the the LCD.
\r
170 static void prvWriteString( const char *pcString );
\r
173 * Initialisation routine for the UART.
\r
175 static void vSerialInit( void );
\r
178 * Thread safe write to the PDC.
\r
180 static void prvPDCWrite( char cAddress, char cData );
\r
183 * Function to simply set a known value into the general purpose registers
\r
184 * then read them back to ensure they remain set correctly. An incorrect value
\r
185 * being indicative of an error in the task switching mechanism.
\r
187 void prvSetAndCheckRegisters( void );
\r
190 * Latch the LED that indicates that an error has occurred.
\r
192 void vSetErrorLED( void );
\r
195 * Sets up the PLL and ports used by the demo.
\r
197 static void prvSetupHardware( void );
\r
199 /*-----------------------------------------------------------*/
\r
201 /* Error flag set to pdFAIL if an error is encountered in the tasks/co-routines
\r
202 defined within this file. */
\r
203 unsigned portBASE_TYPE uxErrorStatus = pdPASS;
\r
205 /* The next character to transmit. */
\r
206 static char cNextChar;
\r
208 /* The queue used to transmit characters from the interrupt to the Comms Rx
\r
210 static QueueHandle_t xCommsQueue;
\r
212 /*-----------------------------------------------------------*/
\r
216 /* Create the queue used to communicate between the UART ISR and the Comms
\r
218 xCommsQueue = xQueueCreate( mainRX_QUEUE_LEN, sizeof( char ) );
\r
220 /* Setup the ports used by the demo and the clock. */
\r
221 prvSetupHardware();
\r
223 /* Create the co-routines that flash the LED's. */
\r
224 vStartFlashCoRoutines( mainNUM_FLASH_CO_ROUTINES );
\r
226 /* Create the co-routine that initiates the transmission of characters
\r
228 xCoRoutineCreate( vSerialTxCoRoutine, mainTX_CO_ROUTINE_PRIORITY, mainTX_CO_ROUTINE_INDEX );
\r
230 /* Create the LCD and Comms Rx tasks. */
\r
231 xTaskCreate( vLCDTask, "LCD", configMINIMAL_STACK_SIZE, NULL, mainLCD_TASK_PRIORITY, NULL );
\r
232 xTaskCreate( vCommsRxTask, "CMS", configMINIMAL_STACK_SIZE, NULL, mainCOMMS_RX_TASK_PRIORITY, NULL );
\r
234 /* Start the scheduler running the tasks and co-routines just created. */
\r
235 vTaskStartScheduler();
\r
237 /* Should not get here unless we did not have enough memory to start the
\r
242 /*-----------------------------------------------------------*/
\r
244 static void prvSetupHardware( void )
\r
246 /* Setup the PLL. */
\r
247 SysCtlClockSet( SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_6MHZ );
\r
249 /* Initialise the hardware used to talk to the LCD, LED's and UART. */
\r
251 vParTestInitialise();
\r
254 /*-----------------------------------------------------------*/
\r
256 void vApplicationIdleHook( void )
\r
258 /* The co-routines are executed in the idle task using the idle task
\r
262 /* Schedule the co-routines. */
\r
263 vCoRoutineSchedule();
\r
265 /* Run the register check function between each co-routine. */
\r
266 prvSetAndCheckRegisters();
\r
269 /*-----------------------------------------------------------*/
\r
271 static void prvWriteString( const char *pcString )
\r
273 /* Write pcString to the LED, pausing between each character. */
\r
274 prvPDCWrite(PDC_LCD_CSR, LCD_CLEAR);
\r
277 vTaskDelay( mainCHAR_WRITE_DELAY );
\r
278 prvPDCWrite( PDC_LCD_RAM, *pcString );
\r
282 /*-----------------------------------------------------------*/
\r
284 void vLCDTask( void * pvParameters )
\r
286 unsigned portBASE_TYPE uxIndex;
\r
287 const unsigned char ucCFGData[] = {
\r
288 0x30, /* Set data bus to 8-bits. */
\r
291 0x3C, /* Number of lines/font. */
\r
292 0x08, /* Display off. */
\r
293 0x01, /* Display clear. */
\r
294 0x06, /* Entry mode [cursor dir][shift]. */
\r
295 0x0C /* Display on [display on][curson on][blinking on]. */
\r
298 /* The strings that are written to the LCD. */
\r
299 const char *pcStringsToDisplay[] = {
\r
303 "www.FreeRTOS.org",
\r
307 /* Configure the LCD. */
\r
309 while( uxIndex < sizeof( ucCFGData ) )
\r
311 prvPDCWrite( PDC_LCD_CSR, ucCFGData[ uxIndex ] );
\r
313 vTaskDelay( mainCHAR_WRITE_DELAY );
\r
316 /* Turn the LCD Backlight on. */
\r
317 prvPDCWrite( PDC_CSR, 0x01 );
\r
319 /* Clear display. */
\r
320 vTaskDelay( mainCHAR_WRITE_DELAY );
\r
321 prvPDCWrite( PDC_LCD_CSR, LCD_CLEAR );
\r
326 /* Display the string on the LCD. */
\r
327 prvWriteString( pcStringsToDisplay[ uxIndex ] );
\r
329 /* Move on to the next string - wrapping if necessary. */
\r
331 if( *( pcStringsToDisplay[ uxIndex ] ) == 0x00 )
\r
334 /* Longer pause on the last string to be sent. */
\r
335 vTaskDelay( mainSTRING_WRITE_DELAY * 2 );
\r
338 /* Wait until it is time to move onto the next string. */
\r
339 vTaskDelay( mainSTRING_WRITE_DELAY );
\r
342 /*-----------------------------------------------------------*/
\r
344 static void vCommsRxTask( void * pvParameters )
\r
346 static char cRxedChar, cExpectedChar;
\r
348 /* Set the char we expect to receive to the start of the string. */
\r
349 cExpectedChar = mainFIRST_TX_CHAR;
\r
353 /* Wait for a character to be received. */
\r
354 xQueueReceive( xCommsQueue, ( void * ) &cRxedChar, mainCOMMS_RX_DELAY );
\r
356 /* Was the character recived (if any) the expected character. */
\r
357 if( cRxedChar != cExpectedChar )
\r
359 /* Got an unexpected character. This can sometimes occur when
\r
360 reseting the system using the debugger leaving characters already
\r
361 in the UART regsters. */
\r
362 uxErrorStatus = pdFAIL;
\r
364 /* Resync by waiting for the end of the current string. */
\r
365 while( cRxedChar != mainLAST_TX_CHAR )
\r
367 while( !xQueueReceive( xCommsQueue, ( void * ) &cRxedChar, portMAX_DELAY ) );
\r
370 /* The next expected character is the start of the string again. */
\r
371 cExpectedChar = mainFIRST_TX_CHAR;
\r
375 if( cExpectedChar == mainLAST_TX_CHAR )
\r
377 /* We have reached the end of the string - we now expect to
\r
378 receive the first character in the string again. The LED is
\r
379 toggled to indicate that the entire string was received without
\r
381 vParTestToggleLED( mainCOMMS_RX_LED );
\r
382 cExpectedChar = mainFIRST_TX_CHAR;
\r
386 /* We got the expected character, we now expect to receive the
\r
387 next character in the string. */
\r
393 /*-----------------------------------------------------------*/
\r
395 static void vSerialTxCoRoutine( CoRoutineHandle_t xHandle, unsigned portBASE_TYPE uxIndex )
\r
397 TickType_t xDelayPeriod;
\r
398 static unsigned long *pulRandomBytes = mainFIRST_PROGRAM_BYTES;
\r
400 /* Co-routine MUST start with a call to crSTART. */
\r
401 crSTART( xHandle );
\r
405 /* Was the previously transmitted string received correctly? */
\r
406 if( uxErrorStatus != pdPASS )
\r
408 /* An error was encountered so set the error LED. */
\r
412 /* The next character to Tx is the first in the string. */
\r
413 cNextChar = mainFIRST_TX_CHAR;
\r
415 UARTIntDisable( UART0_BASE, UART_INT_TX );
\r
417 /* Send the first character. */
\r
418 if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) )
\r
420 HWREG( UART0_BASE + UART_O_DR ) = cNextChar;
\r
423 /* Move the variable to the char to Tx on so the ISR transmits
\r
424 the next character in the string once this one has completed. */
\r
427 UARTIntEnable(UART0_BASE, UART_INT_TX);
\r
429 /* Toggle the LED to show a new string is being transmitted. */
\r
430 vParTestToggleLED( mainCOMMS_TX_LED );
\r
432 /* Delay before we start the string off again. A pseudo-random delay
\r
433 is used as this will provide a better test. */
\r
434 xDelayPeriod = xTaskGetTickCount() + ( *pulRandomBytes );
\r
437 if( pulRandomBytes > mainTOTAL_PROGRAM_MEMORY )
\r
439 pulRandomBytes = mainFIRST_PROGRAM_BYTES;
\r
442 /* Make sure we don't wait too long... */
\r
443 xDelayPeriod &= mainMAX_TX_DELAY;
\r
445 /* ...but we do want to wait. */
\r
446 if( xDelayPeriod < mainMIN_TX_DELAY )
\r
448 xDelayPeriod = mainMIN_TX_DELAY;
\r
451 /* Block for the random(ish) time. */
\r
452 crDELAY( xHandle, xDelayPeriod );
\r
455 /* Co-routine MUST end with a call to crEND. */
\r
458 /*-----------------------------------------------------------*/
\r
460 static void vSerialInit( void )
\r
462 /* Enable the UART. GPIOA has already been initialised. */
\r
463 SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
\r
465 /* Set GPIO A0 and A1 as peripheral function. They are used to output the
\r
467 GPIODirModeSet( GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1, GPIO_DIR_MODE_HW );
\r
469 /* Configure the UART for 8-N-1 operation. */
\r
470 UARTConfigSet( UART0_BASE, mainBAUD_RATE, UART_CONFIG_WLEN_8 | UART_CONFIG_PAR_NONE | UART_CONFIG_STOP_ONE );
\r
472 /* We dont want to use the fifo. This is for test purposes to generate
\r
473 as many interrupts as possible. */
\r
474 HWREG( UART0_BASE + UART_O_LCR_H ) &= ~mainFIFO_SET;
\r
476 /* Enable both Rx and Tx interrupts. */
\r
477 HWREG( UART0_BASE + UART_O_IM ) |= ( UART_INT_TX | UART_INT_RX );
\r
478 IntEnable( INT_UART0 );
\r
480 /*-----------------------------------------------------------*/
\r
482 void vUART_ISR(void)
\r
484 unsigned long ulStatus;
\r
486 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
488 /* What caused the interrupt. */
\r
489 ulStatus = UARTIntStatus( UART0_BASE, pdTRUE );
\r
491 /* Clear the interrupt. */
\r
492 UARTIntClear( UART0_BASE, ulStatus );
\r
494 /* Was an Rx interrpt pending? */
\r
495 if( ulStatus & UART_INT_RX )
\r
497 if( ( HWREG(UART0_BASE + UART_O_FR ) & UART_FR_RXFF ) )
\r
499 /* Get the char from the buffer and post it onto the queue of
\r
500 Rxed chars. Posting the character should wake the task that is
\r
501 blocked on the queue waiting for characters. */
\r
502 cRxedChar = ( char ) HWREG( UART0_BASE + UART_O_DR );
\r
503 xQueueSendFromISR( xCommsQueue, &cRxedChar, &xHigherPriorityTaskWoken );
\r
507 /* Was a Tx interrupt pending? */
\r
508 if( ulStatus & UART_INT_TX )
\r
510 /* Send the next character in the string. We are not using the FIFO. */
\r
511 if( cNextChar <= mainLAST_TX_CHAR )
\r
513 if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) )
\r
515 HWREG( UART0_BASE + UART_O_DR ) = cNextChar;
\r
521 /* If a task was woken by the character being received then we force
\r
522 a context switch to occur in case the task is of higher priority than
\r
523 the currently executing task (i.e. the task that this interrupt
\r
525 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
\r
527 /*-----------------------------------------------------------*/
\r
529 static void prvPDCWrite( char cAddress, char cData )
\r
533 PDCWrite( cAddress, cData );
\r
537 /*-----------------------------------------------------------*/
\r
539 void vSetErrorLED( void )
\r
541 vParTestSetLED( mainCOMMS_FAIL_LED, pdTRUE );
\r
543 /*-----------------------------------------------------------*/
\r
545 void prvSetAndCheckRegisters( void )
\r
547 /* Fill the general purpose registers with known values. */
\r
551 " add r0, r11, #1 \n"
\r
552 " add r1, r11, #2 \n"
\r
553 " add r2, r11, #3 \n"
\r
554 " add r3, r11, #4 \n"
\r
555 " add r4, r11, #5 \n"
\r
556 " add r5, r11, #6 \n"
\r
557 " add r6, r11, #7 \n"
\r
558 " add r7, r11, #8 \n"
\r
559 " add r8, r11, #9 \n"
\r
560 " add r9, r11, #10 \n"
\r
561 " add r10, r11, #11 \n"
\r
562 " add r12, r11, #12"
\r
565 /* Check the values are as expected. */
\r
569 " bne set_error_led \n"
\r
571 " bne set_error_led \n"
\r
573 " bne set_error_led \n"
\r
575 " bne set_error_led \n"
\r
577 " bne set_error_led \n"
\r
579 " bne set_error_led \n"
\r
581 " bne set_error_led \n"
\r
583 " bne set_error_led \n"
\r
585 " bne set_error_led \n"
\r
587 " bne set_error_led \n"
\r
589 " bne set_error_led \n"
\r
591 " bne set_error_led \n"
\r
593 " bne set_error_led \n"
\r
599 "set_error_led: \n"
\r
601 " ldr r1, vSetErrorLEDConst\n"
\r
607 "vSetErrorLEDConst: .word vSetErrorLED"
\r
610 /*-----------------------------------------------------------*/
\r